<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>动画体验</title>
    <style>
        @keyframes a_color{
            100%{
                width: 100%;
                background-color: red;
                font-size: 10px;
            }
            10%{
                width: 10%;
                background-color: rosybrown;
                font-size: 1000px;
            }

            }
        .box{
             animation-name:a_color;
             animation-duration: 2s;
             animation-iteration-count:infinite}
                
    </style>
</head>
<body>
    <div class="box">hello动画</div>
</body>
</html>